Laser beam generating devices are commercially available as laser pointers and other devices that generate a focused, high power laser beam. Commercial laser pointers are readily available to the public and are being used to interfere with pilots while in critical phases of flight operations. The laser beam generated by such devices can be directed at aircraft and reach the cockpit of such aircraft. When the laser beam interacts with the cockpit glass, the laser beam can bloom or glare on the glass and/or travel to the pilot's eyes, thus interfering with the pilot's vision. Unfortunately, the number of such laser beam incidents has nearly doubled in recent years.
Pilots must not only see outside of the aircraft, but they also must see their instruments without any hindrances. When a laser is pointed at an aircraft, such an incident takes a pilot's attention away from the business of getting passengers safely to their destination. Laser pointers can have a dramatic effect on a pilot's vision, especially during critical phases of flight, such as takeoff and landing. Laser strikes can also harm a pilot's vision. For example, when a pilot has been piloting an aircraft in nighttime conditions, a sudden, brilliant green beam of light directly in the eyes can result in persistent pain, eye spasms and spots in the pilot's vision.
While pilots are instructed to look away from a laser beam or close an eye to avoid the laser beam, by the time the pilot looks away or closes an eye, the laser beam has already reached the pilot's eyes. Furthermore, averting the eyes effectively diminishes the pilot's ability to control the airplane.
Specialized sunglasses can reduce the impact of a laser beam on the pilot's eyes, but these devices also restrict the pilot's ability to see the cockpit instruments. Other types of sunglasses inhibit a broad range of wavelengths of light from reaching the pilot's eyes, which can be undesirable at night and other low light conditions and can be dislodged during adverse weather or turbulence only to cause additional distraction. Additionally, sunglasses can also be costly when they are in prescriptive form, can cause glare, and are subject to dust and oil buildup.
Tinted windows suffer from similar drawbacks by inhibiting all wavelengths of light from reaching the pilot's eyes. Auto-dimming glasses or windows gradually dim and may not block the laser beam before the pilot's vision has already been impaired. Additionally, some auto-dimming glass requires a power source.
Existing technologies provide glasses having applied coatings to block intense light. However, these types of glasses restrict all wavelengths of light, thereby dimming the appearance of critical flight instruments and the external view outside of the cockpit.
Similar problems exist for automobile drivers in sunny conditions or when an on-coming car has bright headlight beams.
Accordingly, those skilled in the art continue with research and development efforts in the field of shielding optics, such as human vision, from light interference.